摘要
针对喷杆喷雾机作业过程中,因田间地表起伏和土壤硬度不同导致喷杆与施药靶标面无法始终保持适当距离、影响施药均匀性和防治效果的问题,设计了一种喷杆高度智能调节系统。该系统采用3个超声波测距传感器获取喷杆不同位置的高度信息并用限幅滑动平均滤波算法对传感器数据进行预处理,同时将双轴倾角传感器分别安装于车体底盘中部和喷杆上,以实时获取喷雾机和喷杆的姿态信息。然后采用基于加权平均的多传感器融合算法对喷杆高度信息进行融合处理。利用专家知识和经验,综合考虑当前喷雾机姿态信息和喷杆高度信息,设计使用不同的控制参数和控制规则,再由专家控制推理机按照制定的控制策略进行推理输出。然后控制机构通过PWM控制电磁比例换向阀动作,驱动喷杆调节油缸对喷杆高度进行调节,使喷杆高度误差快速稳定在允许误差范围内。给出了喷杆系统的机械结构,阐述了系统硬件系统组成、工作原理和喷杆高度智能调节系统的专家控制算法和软件实现。系统通过CAN总线实时获取外部变量施药系统的工作状态信息,实现与变量施药系统的工作同步,同时由触摸屏实现人机交互,设定放大系数、衰减系数、动作阈值等控制参数,再通过CAN总线输送至控制器用于喷杆高度控制。系统应用于课题组研制的3WZG3000A型大型喷雾机,并针对喷杆高度智能调节系统的调节性能进行了试验。试验结果表明,该系统可以快速跟随阶跃激励引起的喷杆高度调节需求,当喷杆高度控制允许误差设定为8%、阶跃激励为20 cm时,最大调节时间不大于0.75 s。
In order to ensure the application effect of plant protection,the proper distance between spray boom and plant canopy need to be maintained when field surface relief and soil hardness were changed during the whole working period.Three ultrasonic distance measuring sensors were used to obtain the height information of spray boom,and the sensors data were preprocessed with amplitude-limiting and moving average algorithm.Two dual-axis inclination sensors were used to obtain the posture information of sprayer and spray boom which were installed on the chassis of sprayer and spray boom respectively.And then multi-sensor fusion algorithm based on weighted average was used to handle the spray boom height information.Then different control strategies were designed for different working states of sprayer by using expert knowledge and experience.According to the established control strategy,the control signal was outputted by the inference engine of expert control to control mechanism which was used to drive the spray boom height adjustment cylinder.The mechanical structure of the boom system was introduced,and the composition and working principle of the boom height intelligent adjustment system(BHIAS)were described.The control algorithm and software realization of BHIAS were elaborated.The work status of external variable spraying system was obtained by CAN bus to achieve synchronization of work status between BHIAS and variable spraying system.The touch screen was used to achieve human-computer interaction and control parameters was sent to the controller for boom height control,such as amplification coefficient,attenuation coefficient,adjustment tolerance,etc.The BHIAS was applied to 3WZG3000A boom sprayer which was developed by the research group.Ground tests were conducted separately for testing the adjustment performance of BHIAS.The test results showed that BHIAS can follow the boom height adjustment requirements which was caused by step excitation quickly.When the allowable error of boom height adjustment was 8%and the height of step excitation was 20 cm,the maximum adjustment time of BHIAS was no more than 0.75 s.
作者
孙星
杨学军
董祥
张铁
严荷荣
王之东
SUN Xing;YANG Xuejun;DONG Xiang;ZHANG Tie;YAN Herong;WANG Zhidong(Chinese Academy of Agricultural Mechanization Sciences,Beijing 100083,China;State Key Laboratory of Soil Plant Machinery System Technology,Beijing 100083,China;Modern Agricultural Equipment Co.,Ltd.,Beijing 100083,China)
出处
《农业机械学报》
EI
CAS
CSCD
北大核心
2020年第S02期275-282,共8页
Transactions of the Chinese Society for Agricultural Machinery
基金
国家重点研发计划项目(2017YFD0700903、2016YFD0200705)
国家马铃薯产业技术体系项目(CARS09)。
